[topgen/tlgen] Multi-tiered Xbar
The script is to support multi-tiered crossbars on top_earlgrey.
Now any crossbar can have connections to other crossbars. It is allowed
only one connection between two crossbars at this time.
If `xbar: "true"` is defined in the node, the tool does below:
- Recognize it as a crossbar connection
- Gather downstream addresses and calculate the common address range (*)
- If device is a port to another crossbar, the address steering compares
list of address range not a single `address_from`, `address_to`
Signed-off-by: Eunchan Kim <eunchan@opentitan.org>
diff --git a/util/tlgen/lib.py b/util/tlgen/lib.py
new file mode 100644
index 0000000..528de26
--- /dev/null
+++ b/util/tlgen/lib.py
@@ -0,0 +1,21 @@
+# Copyright lowRISC contributors.
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+
+import math
+import logging as log
+
+
+def is_pow2(v):
+ """Return true if value is power of two
+ """
+ if not isinstance(v, int):
+ log.warning("is_pow2 received non-integer value {}".format(v))
+ return False
+ t = 1
+ while t <= v:
+ if t == v:
+ return True
+ t = t * 2
+
+ return False
